Condensation of 2-(chloromethyl)quinazolin-4(3H)-one (1) with benzo[d]imidazole-2-thiol (2) in acetone containing triethylamine as a base gave 2-(((1H-benzo[d]imidazol-2-yl)thio)methyl)quinazolin-4(3H)-one (3). The later was treated with DMS (dimethyl sulphate) 1:2 ratio in DMF afforded 3-methyl-2-(((1-methyl-1H-benzo[d]imidazol-2- yl)thio)methyl)quinazolin-4(3H)-one (4). The latter was reacted with H2O2 for 3 hr obtained 3-Methyl-2-(((1-methyl- 1H-benzo[d]imidazol-2-yl)sulfonyl)methyl)quinazolin-4(3H)-one (5). 5 could also be prepared by treating 3 with H2O2 followed by reaction with DMS in 1:2 ratios in DMF for 2 hr. The structures of all the new compounds synthesized in the work have been established on the basis of their spectroscopic data.